OLED (organic light emitting diode) display device with self-luminous, wide viewing angle, high luminous efficiency, low power consumption, fast response time, low temperature characteristics, simple manufacturing process, low cost. Flexible OLED display device with its light weight, flexible, easy to carry the advantages of wearable equipment to bring a far-reaching impact on the future of flexible OLED display device will continue to penetrate with the personal intelligence terminal to be more widely used.
The core component of the OLED display device is an OLED display panel, and the structure of the OLED display panel generally includes: a TFT array substrate, and an anode layer, a pixel definition layer, a first common layer, a light emitting layer, a second common layer, and a cathode layer sequentially fabricated on the TFT substrate. The anode layer includes a plurality of arrays of anodes arranged, the pixel defining layer includes a plurality of pixel openings corresponding to the anode one by one; the first common layer completely covers the pixel definition layer and the anode layer (in the structure layer for a continuous coverage), the first common layer may include a plurality of sub-functional layers; the light-emitting layer includes a plurality of light-emitting cells corresponding to the pixel openings, the light-emitting units being located within the pixel openings; the second common layer completely covers the light emitting layer and the first common layer (in the structure layer for a continuous coverage), the first common layer may include a plurality of sub-functional layers; the cathode layer overlaps the second common layer.
The OLED display panel works by transferring the holes through the first common layer to the light emitting layer under the action of an electric field between the anode and the cathode, the electrons being transmitted through the second common layer to the light emitting layer, the holes and electrons recombine and then emit light within the light emitting layer. The OLED display panel is usually by the R, G, B three primary colors to achieve a different color of the display, so OLED display panel of a pixel usually contains R, G, B three light-emitting unit, normally, each of the three R, G, and B light emitting units can be individually controlled by the driving circuit, specifically, the cathode layers of the three light-emitting units of R, G, and B are common, and the anodes are independent from each other, by controlling the anode corresponding to each light-emitting unit, a separate driving of each light-emitting unit can be realized.
With the improvement of the display panel resolution, the number of light emitting units per unit area is also increasing, resulting in the distance between the light emitting units continue to decrease, R, G, B three light-emitting unit of the light-emitting layer of different materials, the bright voltage is also different. In the structure of the conventional OLED display panel as described above, since the first common layer of the adjacent light emitting cells communicates and the distance between the light emitting units is small in order to improve the resolution, when one of the light emitting cells (target light emitting cells) is lit, a small amount of holes can be injected into the adjacent light emitting cells through the first common layer, recombined with the electrons in the adjacent light emitting cells, which led to the luminous impure of the target light-emitting unit, this phenomenon known as the leakage of light-emitting phenomenon, a small amount of leakage generated by the leakage current leakage current.
When the target light-emitting unit is lit at a high current, a small amount of holes can cause the adjacent light-emitting cells to emit light, but the brightness is relatively weak, will be the target light-emitting unit issued by the strong light cover, the human eye can not identify, at this time the effect of light leakage is small. However, when the target light emitting unit is lit at a low current, the light emitted by the target light emitting unit is weak, and the performance of the light leakage phenomenon is relatively obvious, thereby reducing the display effect of the OLED display panel.